The invention relates to a neck rest for the seats of automobiles as claimed in claim 1.
Commonly, neck rests comprise a cushion member which is displaceably mountable by means of two rods in the back rest of a sear, the rods being inserted in neck rest sleeves of the back rests. The cushion member is retained by a support member which is fixedly connected to the neck rest rods.
As a general rule, neck rests are arranged in a wrong or inadequate manner in a vehicle, in a position which is not always adapted to the driver""s or front-seat passengers needs. If an accident occurs by a rear-end collision a large distance between the head and the neck rest causes heavy strains in the nape of the neck, which might result in significant lesions to the nuchal region. In particular, misadjustment is provoked by too low a position of the neck rest on the back of the seat.
It has become known from DE 39 00 495 to provide a displaceable cushion member. It has become known from DE 199 47 309 to provide a front-end pivotable neck rest member which is pivotally supported about an upper horizontal axis and is actuated, for instance, by an airbag.
It is the object of the invention to configure a neck rest with an extendable cushion member in a way such as to assume a position, in a response case, which ensures an efficient interception of forces acting upon the head of a person.
The object is achieved by the features of claim 1.
In the inventive neck rest, a second support member is pivotally supported on the first support member about a lower horizontal axis. The actuation means include spring means which bias the second support member towards the pivoted position. A controllable locking means retains the second support member in an extended position relative to the first support member against the spring. A third support member is displaceably supported on the second support member between a lower and an upper position. The third support means is biased towards the upper position by a second spring means. A controllable second locking means retains the third support member in the lower position, the second locking means being unlocked when the second support member has attained a predetermined pivoting angle. Finally, stop means are provided which act between the second and/or third support member and the first support member when the second and third support members have attained their extended position. The stop means provide for the second and third support members to remain in the extended position and absorb the force when the head exerts an appropriate force towards the first support member.
The fact that a second support member is provided may ensure that the third support member has an optimum position relatively close to the head in which the nape of the neck or the back of the head of a person sitting on the seat shoots to the rear because of a collision bump. Although the second support member will then be extended to the front towards the sitting person the second support member is directly or obliquely pushed to the top so that a bump acting towards the head of the sitting person will not occur. In fact, when supported appropriately, the third support member helps achieve a position in which an optimum force absorption is attained with the sitting person facing no risk of injury.
The second support member requires to be locked in the retracted position. This can be accomplished by means of a pawl pivotally supported on the first support member which grips behind an edge or undercut on the second support member. The pawl can be actuated in an appropriate manner, e.g. via a Bowden cable, so that if an accident occurs unlocking is possible immediately.
According to an aspect of the invention, the first spring means are formed by a leaf spring or leg spring. The second spring means are preferably a so-called roll spring which, when in the retracted position, i.e. rolled-up position, applies a bias to the third support member.
According to another aspect of the invention, the first support member has formed thereon at least one stop surface which cooperates with an extension of the third or second support members, the extension facing towards the first support member. When the third support member is displaced into the extended position on the second support member the extension is capable of continuously cooperating with the stop surface so that stabilization is ensured in any position. A further surface located below the stop surface thus enables the extension to cooperate with said lower surface so as to lock the third support member in the lower position.
A guiding surface is disposed between the second and third support members to allow the third support member to be moved along the second support member. According to an aspect of the invention, said guiding surface is curved like an bow so that the above described upward motion of the third support member is brought about at least at the end of the displacement path.
The second support member is hinged to the first one above the pivoting axis to make the second support member pivot only at a predetermined angle. This hinge can be realized by a rope or even by a toggle joint.